CTX PR705F and its geometry

edited January 2016 in Hardware
In conjunction with my promise on another post, I'm posting this.
I recently got ahold of this CTX monitor to replace an ancient Sony that had a tube failure. (diagnosed as electron gun problem)
The new monitor has far better resolution- 1600x1200 vs 1280x1024. However, it has two flaws. One it has a minor scratch on the front, and the second being its horrible geometry. Initially it was horrible to begin with, but after spending 4 hours on a Saturday setting it, the geometry still wasn't right.
Left side arched inwards, and a few cm were missing off the bottom right.
The "recall" or reset doesn't work as it results in a "no user preset available". I've degaussed it, no difference.
Even funnier is when I hooked it up to a different machine, the Geometry became WORSE. Nothing could rectify it.

Any solutions here? It uses a 17" 1600x1200 Trinitron, and I have yet to open it to get the model of the tube.
I can't really get rid of it, not without paying 50 euro for a recycling fee so that's off the table.

Basic specs: PCWorld Specs
Reading off google, I'm not the only one with this problem, but I couldn't find a solution other than send it off for RMA.


  • Crack it open and see if there is any adjustable pots on the PCB for calibrating it. I had to do that will a DELL monitor I had that was a rebrand CTX.
  • TCPMeta wrote:
    Crack it open and see if there is any adjustable pots on the PCB for calibrating it. I had to do that will a DELL monitor I had that was a rebrand CTX.
    Thanks, wasn't expecting a helpful response that quick. (sent it off to be cleaned last week)
    Did you also experience the issue where @ 640x480 the image would be reduced to a tile 10x10cm?
  • Never tried it lower then 800x600.
  • Here's a shot of the PCB on the yoke. This look anywhere like yours?
    There are four pots, and one large variable switch at the bottom right.
    Leaving image link asis as direct-linking doesn't work right with this image.
    The two things that concern me is the poor convergence towards the right side of the monitor and the upward curving ("hill" goes upward) rather than downward at the top to follow the natural curve of the tube.
    Luckily the pots have pointer dots so I don't have to count turns. So I'll just turn them until I get the results I want.
  • Looks like variable resistors. VR2 and VR3 are 20ohm and VR1 is 500ohm. Also it looks like you got another one on the left side labeled VR4 but too blurry to see the value.

    Best bet is to use a insulated Potentiometer screw driver
    Carefully turn them slowly while the monitor is on. Just avoid the flyback transformer and cable that goes to the tube. You can use a mirror to see the picture tube or a second person to make things easier.
    There should also be a couple of pots built into the flyback transformer but that is for Focus but the only time that is messed with is at the factory and only changed if the tube has been replaced.
  • I have an insulated screw driver that perfectly fits, and I'm having a friend set the pots while I sit in front of it.
    The other one is labeled vr4, and the far right one got blurred in the shot, so I corrected it.

    Anyways, I'll set it this weekend when I have time.

    I will say, XP for some reason just looks better on this monitor than 7.
  • Probably differences in font smoothing. Windows Vista and up will have ClearType on by default, and that relies on how LCD subpixels work for ideal visuals.
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